JP2004125427A

JP2004125427A - Gas and temperature detecting device

Info

Publication number: JP2004125427A
Application number: JP2002285872A
Authority: JP
Inventors: Takamasa Osawa; 大澤　敬正; Yuji Kimoto; 木元　祐治
Original assignee: NGK Spark Plug Co Ltd
Current assignee: Niterra Co Ltd
Priority date: 2002-09-30
Filing date: 2002-09-30
Publication date: 2004-04-22

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas and temperature detecting device capable of properly detecting a temperature of a measured object such as an outside air temperature of a device by a temperature sensor element without being affected by the heat from a heat source, by preventing the heat generated from the heat source of a gas sensor element from conducting to the temperature sensor element through a wiring board. <P>SOLUTION: This gas and temperature detecting device 100 comprises the gas sensor element 140 including an electric heater element 143 and detecting the gas concentration, a thermistor 150 detecting the outside air temperature and the like, and the wiring board 130 for mounting the gas sensor element 140 and the thermistor 150. The wiring board 130 is provided with first void part 131, a second void part 132, a third void part 133 and a forth void part 134 penetrated in the thickness direction for preventing the conduction of the heat generated from the electric heater element 143 to the thermistor 150 through the wiring board 130. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、ガスセンサ素子と感温素子とを有するガス及び温度検知装置に関する。
【０００２】
【従来の技術】
従来より、ガスセンサ素子と外気温センサとを有するガス及び温度検知装置が知られている（例えば、特許文献１参照）。ところで、このガス及び温度検知装置で用いられるガスセンサ素子は、感ガス体とヒータとを有し、感ガス体をヒータで加熱して高温に保った状態で使用する。
【０００３】
【特許文献１】
特開２０００−１４２０９７号公報（第３図）
【０００４】
【発明が解決しようとする課題】
しかし、このガス及び温度検知装置のように、ガスセンサ素子と温度センサとを１つの基板に実装すると、ヒータで発生した熱が基板を通じて感温素子に伝わってしまう。このため、感温素子自身の温度が上昇してしまい、外気温を適切に検知することができなくなる虞があった。
【０００５】
本発明は、かかる現状に鑑みてなされたものであって、ガスセンサ素子の熱源から発生する熱が配線基板を通じて感温素子に伝わるのを妨げ、感温素子によって装置外部の外気温など測定対象の温度を、熱源からの熱に影響されることなく適切に検知することができるガス及び温度検知装置を提供することを目的とする。
【０００６】
【課題を解決するための手段、作用及び効果】
その解決手段は、熱源を含み特定のガスの濃度変化を検知するガスセンサ素子と、温度を検知する感温素子と、上記ガスセンサ素子及び上記感温素子を実装する配線基板と、を備えるガス及び温度検知装置であって、上記配線基板は、その厚さ方向に貫通して形成され、上記熱源から上記配線基板を通じて、熱が上記感温素子に伝わるのを妨げる空隙部を有するガス及び温度検知装置である。
【０００７】
本発明のガス及び温度検知装置では、配線基板に空隙部を設けることによって、ガスセンサ素子の熱源で発生する熱が、配線基板を通じて感温素子に伝わるのを妨げることができる。配線基板に空隙部を設けることで、この部分が気体に代わって熱伝導率が低下するからである。このため、本発明のガス及び温度検知装置では、熱源からの熱による感温素子への影響を防ぎ、測定対象の温度、例えば、ガス及び温度検知装置の外部の温度（車室外の外気温など）を感温素子によって適切に検知することが可能となる。
【０００８】
なお、熱源を含むガスセンサ素子としては、例えば、感ガス体とヒータとを組合わせて一体に形成したもの、感ガス体とヒータとが別体のもの、ヒータ自身を感ガス体にしたもの（例えば、金属コイルの表面にＳｎＯ２等の金属酸化物半導体を塗布して焼結したもの）が挙げられる。感温素子としては、温度を検知できるものであれば良く、代表的なものとして、サーミスタが挙げられる。また、配線基板をその厚さ方向に貫通する空隙部とは、配線基板に形成した貫通孔の他に、配線基板の外周面を凹状とした切り欠きをも含む。
【０００９】
さらに、上記ガス及び温度検知装置であって、前記配線基板の前記空隙部は、前記ガスセンサ素子の前記熱源を上記配線基板に対し上記配線基板の厚さ方向に投影した熱源投影部と前記感温素子を上記配線基板に対し上記配線基板の厚さ方向に投影した感温投影部とを結んだ仮想直線の一部を含むガス及び温度検知装置とすると良い。
【００１０】
本発明のガス及び温度検知装置では、配線基板の空隙部が、熱源投影部と感温投影部とを結んだ仮想直線の一部を含むように形成されている。すなわち、配線基板の空隙部は、ガスセンサ素子の熱源で発生する熱が配線基板を通じて感温素子に最も伝わり易い最短熱伝導経路上に位置している。このため、熱源で発生した熱が配線基板を通じて感温素子に伝わるのを、効率良く妨げることができる。
【００１１】
さらに、上記いずれかのガス及び温度検知装置であって、前記配線基板の前記空隙部は、前記ガスセンサ素子の前記熱源を上記配線基板に対し上記配線基板の厚さ方向に投影した熱源投影部及びその周縁部の少なくともいずれかに形成されてなるガス及び温度検知装置とすると良い。
【００１２】
本発明のガス及び温度検知装置では、配線基板の空隙部が、ガスセンサ素子の熱源を配線基板に対し上記配線基板の厚さ方向に投影した熱源投影部及びその周縁部の少なくともいずれかに形成されている。すなわち、配線基板のうち熱源に近い位置に空隙部を形成している。このため、本発明のガス及び温度検知装置は、熱源で発生した熱が感温素子へ伝わるのを早い段階で効率良く妨げることができる。
【００１３】
さらに、上記ガス及び温度検知装置であって、前記空隙部は、少なくとも２つの隣り合う空隙部であり、前記配線基板は、上記少なくとも２つの隣り合う空隙部の間を通る配線を有するガス及び温度検知装置とすると良い。
【００１４】
本発明のガス及び温度検知装置の配線基板には、熱源投影部及びその周縁部の少なくともいずれかに形成された少なくとも２つの隣り合う空隙部の間を通る配線が形成されている。このため、この配線を用いて、熱源あるいは空隙部より熱源側の領域に位置する電子部品と熱源の反対側の領域に位置する電子部品とを電気的に接続させることができる。すなわち、熱源投影部及びその周縁部の少なくともいずれかに少なくとも２つの隣り合う空隙部を形成することで熱源から発生する熱の伝達を妨げつつも、簡易に、熱源あるいは空隙部より熱源側の領域に位置する電子部品と熱源の反対側の領域に位置する電子部品とを電気的に接続することができる。
【００１５】
さらに、上記いずれかのガス及び温度検知装置であって、前記配線基板の前記空隙部は、前記感温素子を上記配線基板に対し上記配線基板の厚さ方向に投影した感温投影部及びその周縁部の少なくともいずれかに形成されてなるガス及び温度検知装置とすると良い。
【００１６】
本発明のガス及び温度検知装置では、配線基板の空隙部が、感温素子を配線基板に対し上記配線基板の厚さ方向に投影した感温投影部及びその周縁部の少なくともいずれかに形成されている。すなわち、配線基板のうち感温素子に近い位置に空隙部を形成している。このため、熱源から配線基板を通じて感温素子付近まで伝わってきた熱が、最終的に感温素子に伝わらないようにすることができる。
【００１７】
さらに、上記いずれかのガス及び温度検知装置であって、前記配線基板の前記空隙部の角部は弧状に形成されてなるガス及び温度検知装置とすると良い。
【００１８】
ガス及び温度検知装置は、配線基板に実装されたガスセンサ素子及び感温素子等の電子部品と配線基板との熱膨張差や外部の振動の影響で、配線基板に応力が生じることがある。このため、例えば、配線基板に形成した空隙部の外周の角部が角形状であると、この角部に応力が集中し、この部分から配線基板に亀裂が発生する虞がある。これに対し、本発明のガス及び温度検知装置では、配線基板の空隙部の角部を弧状としている。このようにすることで、熱膨張差や振動の影響で空隙部の角部に応力が集中するがなく、配線基板の破損を防止できる。なお、空隙部の角部が弧状とは、例えば、角部が円弧状（Ｒ形状）、楕円弧形状のものが挙げられる。従って、角部を弧状とした結果、空隙部全体が楕円形状、円形状となった場合も含まれる。
【００１９】
さらに、上記いずれかのガス及び温度検知装置であって、前記配線基板の前記空隙部は貫通孔であるガス及び温度検知装置とすると良い。
【００２０】
ガス及び温度検知装置は、配線基板に実装されたガスセンサ素子や感温素子等の電子部品と配線基板との熱膨張差や外部の振動の影響で、配線基板に応力が生じることがある。このため、空隙部が、例えば、配線基板の外周面を凹状とした切り欠きである場合には、配線基板のうち幅細となる部分が１カ所形成されることとなるので、配線基板の平面に沿う方向の剛性が低くなることがある。このため、この切り欠き部分から配線基板に亀裂が発生する虞がある。これに対し、本発明のガス及び温度検知装置では、配線基板の空隙部を貫通孔としている。このため、空隙部全体を配線基板で囲むこととなり、幅細となる部分が空隙部を挟んで２カ所形成されるので、切り欠きを形成した場合に比して、配線基板の平面に沿う方向の剛性が高く保たれ、熱膨張差や振動の影響で配線基板が破損することを防止できる。
【００２１】
さらに、上記いずれかのガス及び温度検知装置であって、前記感温素子は、前記配線基板の縁部に配置されてなるガス及び温度検知装置とすると良い。
【００２２】
一般に、配線基板の縁部は基板外部に近いために、熱が外部に放出されやすく、配線基板の平面方向内部に比して低温となる。本発明のガス及び温度検知装置では、感温素子を配線基板の縁部に配置している。従って、感温素子を配線基板に投影した感温投影部が、配線基板の縁部となる。このため、熱源から感温投影部に伝わった熱は基板外部へ放出され、感温投影部は配線基板の平面方向内部に比して低温となるので、感温素子は熱源から発生した熱に影響されにくくなる。
【００２３】
さらに、上記ガス及び温度検知装置であって、前記感温素子は、前記配線基板の前記縁部のうち前記ガスセンサ素子の前記熱源から最も離れた位置に配置されてなるガス及び温度検知装置とすると良い。
【００２４】
本発明のガス及び温度検知装置では、配線基板の縁部のうちガスセンサ素子の熱源から最も離れた位置に、感温素子を配置している。このため、感温素子は熱源から発生した熱に、より一層影響されにくくなる。
【００２５】
さらに、上記いずれかのガス及び温度検知装置であって、前記ガスセンサ素子、前記感温素子、及び前記配線基板を収納するケーシングを備え、上記ケーシングは、上記ケーシング外部の気体を上記ケーシング内部に導入する通気孔と、上記通気孔から導入された上記気体を上記配線基板の前記空隙部まで導く経路と、を有するガス及び温度検知装置とすると良い。
【００２６】
本発明のガス及び温度検知装置では、外部から通気孔を通じて導入された気体が配線基板の空隙部まで導かれる。このため、空隙部において、配線基板を伝わる熱が気体を通じて外部に放散される。従って、感温素子は、熱源から発生した熱に影響されにくくなる。
【００２７】
さらに、上記ガス及び温度検知装置であって、前記ケーシングは、前記通気孔から導入された前記気体を前記配線基板の前記感温素子まで導く経路を有するガス及び温度検知装置とすると良い。
【００２８】
本発明のガス及び温度検知装置では、さらに、外部から通気孔を通じて導入された気体が感温素子まで導かれる。このため、感温素子は、外部から導入された気体によって冷却される。またこれと共に、ケーシング外部の気温（外気温）を適切に検知することが可能となる。
【００２９】
さらに、上記いずれかのガス及び温度検知装置であって、前記配線基板のうち前記感温素子を上記配線基板に対し上記配線基板の厚さ方向に投影した感温投影部の周縁部には、上記ガス及び温度検知装置の外部と電気的に接続するコネクタピンが固着されてなるガス及び温度検知装置とすると良い。
【００３０】
ガス及び温度検知装置では、例えば、コネクタピンと係合する端子金具を一端に有する電線を外部からコネクタピンに接続することで、配線基板がコネクタピンを通じて外部と電気的に接続することになる。このとき、配線基板は、コネクタピンを通じて外部と熱的にも接続することとなる。具体的には、配線基板のうちコネクタピンの周縁部の熱がコネクタピンを通じて配線に伝わり、この配線から熱が外部に放散される。そこで、本発明のガス及び温度検知装置では、配線基板のうち感温投影部の周縁部に外部と電気的に接続するコネクタピンを配置するようにした。このようにすることで、配線基板のうち感温投影部の周縁部の熱がコネクタピンを通じて外部に放出されるので、感温素子は熱源から発生した熱に影響されにくくなる。
【００３１】
【発明の実施の形態】
（実施形態）
本発明の実施の形態であるガス及び温度検知装置１００について、図面を参照しつつ説明する。本実施形態のガス及び温度検知装置１００は、図１に示すように、第１ケーシング部材１１０、第２ケーシング部材１２０、及び配線基板１３０を有する。配線基板１３０は、第１ケーシング部材１１０と第２ケーシング部材１２０とを組合わせて一体となったケーシング１６０内に収納される。
第１ケーシング部材１１０は、樹脂一体成型した蓋形状で、ガスセンサ素子１４０を収容するガスセンサ素子収容部１１２、外気をケーシング１６０内に導入する通気孔１１２ｂ、及び外部と電気的に接続する端子コネクタ部１１３を有している。第２ケーシング部材１２０は、樹脂一体成型した箱形状で、ガス及び温度検知装置１００を自動車のボディや車両用空調装置のダクト等に取付けるための取付け部１２２を有している。
【００３２】
配線基板１３０は、ガラス布基材エポキシ樹脂からなり、その主面１３０ｆには、ガス濃度を検知するガスセンサ素子１４０、外気温を検知するサーミスタ１５０が実装されている。
ここで、図１に分解して示したガス及び温度検知装置１００を組付けて一体にしたガス及び温度検知装置１００の側面視断面図を図２に示す。図２に示すように、ガスセンサ素子１４０は、第１感ガス体１４１、第２感ガス体１４２、及び電気ヒータ素子１４３を実装したアルミナ基板１４５と、通気孔１４６ｂを有しアルミナ基板１４５を包囲する外筒１４６と、４つの素子端子部１４７とを有する。第１感ガス体１４１は、ＮＯｘ等の酸化性ガスの濃度変化によりセンサ抵抗値が変化するものである（例えば、ＷＯ３を主体に構成したもの）。第２感ガス体１４２は、ＨＣ、ＣＯ等の還元性ガスの濃度変化によりセンサ抵抗値が変化するものである（例えば、ＳｎＯ２を主体に構成したもの）。電気ヒータ素子１４３は、第１，第２感ガス体１４１，１４２を加熱するためのものである。素子端子部１４７は、一端が第１，第２感ガス体１４１，１４２、電気ヒータ素子１４３、及びこれら共通のＧＮＤに接続され他端が外筒１４６の外部にまで延設されている。このようなガスセンサ素子１４０は、素子端子部１４７を配線基板１３０に設けられた基板端子１３８に接続することで、配線基板１３０に実装される。
なお、本実施形態では、電気ヒータ素子１４３が熱源に相当し、サーミスタ１５０が感温素子に相当する。また、ガスセンサ素子１４０については、上記構成に限定されないことはいうまでもない。
【００３３】
次に、配線基板１３０の平面図を図３に示す。図３に示すように、配線基板１３０には、ガスセンサ素子１４０の電気ヒータ素子１４３で発生する熱が配線基板１３０を通じてサーミスタ１５０に伝わるのを妨げるために、配線基板１３０を厚さ方向に貫通するスリット形状の第１空隙部１３１、第２空隙部１３２、第３空隙部１３３、第４空隙部１３４が形成されている。特に、第２空隙部１３２及び第４空隙部１３４は、電気ヒータ素子１４３を配線基板１３０に投影したヒータ投影部１３０ｂとサーミスタ１５０を配線基板１３０に投影したサーミスタ投影部１３０ｃとを結んだ仮想直線Ｌの一部を含むように形成されている。すなわち、第２空隙部１３２及び第４空隙部１３４は、電気ヒータ素子１４３で発生する熱が配線基板１３０を通じてサーミスタ１５０に最も伝わり易い最短熱伝導経路上に位置している。このため、電気ヒータ素子１４３で発生した熱が配線基板１３０を通じてサーミスタ１５０に伝わるのを効率良く妨げることができる。
【００３４】
さらに、第１空隙部１３１、第２空隙部１３２、第３空隙部１３３は、電気ヒータ素子１４３を配線基板１３０に投影したヒータ投影部１３０ｂの周縁部に形成されている。すなわち、配線基板１３０のうち電気ヒータ素子１４３に近い位置に第１空隙部１３１、第２空隙部１３２、第３空隙部１３３を形成している。
このため、電気ヒータ素子１４３で発生した熱が、配線基板１３０のヒータ投影部１３０ｂとサーミスタ投影部１３０ｃとの間に位置する中間領域１３０ｄに拡がり、さらにサーミスタ投影部１３０ｃへ伝わるのを早い段階で効率良く妨げることができる。
さらに、第４空隙部１３４は、サーミスタ１５０を配線基板１３０に対し配線基板１３０の厚さ方向に投影したサーミスタ投影部１３０ｃの周縁部に形成されている。すなわち、配線基板１３０のうちサーミスタ１５０に近い位置に第４空隙部１３４を形成している。このため、電気ヒータ素子１４３から配線基板１３０を通じてサーミスタ投影部１３０ｃ付近まで伝わってきた熱が、最終的にサーミスタ１５０に伝わりにくくすることができる。
【００３５】
さらに、ガス及び温度検知装置１００では、図３に示すように、第１空隙部１３１と第２空隙部１３２との間及び第２空隙部１３２と第３空隙部１３３との間を通って、ガスセンサ素子１４０を配線基板１３０に対し配線基板１３０の厚さ方向に投影したガスセンサ投影領域１３０ｅ（２点鎖線で示す円領域）内から図示しないＩＣ、コンデンサ、抵抗器等の電子部品が実装された中間領域１３０ｄ内に延びる配線１３６が形成されている。このため、この配線１３６を用いて、ガスセンサ素子１４０（電気ヒータ素子１４３、第１，第２感ガス体１４１，１４２）と、中間領域１３０ｄ内に実装されているＩＣ等の電子部品とを接続することができる。すなわち、ヒータ投影部１３０ｂの周縁部に隣り合って形成された第１空隙部１３１、第２空隙部１３２、第３空隙部１３３によって電気ヒータ素子１４３から発生する熱の伝達を妨げつつも、これらの空隙部同士の間を通るように配線１３６を形成することによって、ジャンパ線等を用いなくとも、簡単にガスセンサ素子１４０と中間領域１３０ｄ内の電子部品とを電気的に接続することができる。
【００３６】
ところで、ガス及び温度検知装置１００では、配線基板１３０に実装されたガスセンサ素子１４０やサーミスタ１５０等の電子部品と配線基板１３０との熱膨張差や自動車等の振動の影響で、配線基板１３０に応力が生じることがある。これに対し、ガス及び温度検知装置１００では、図３に示すように、配線基板１３０に形成した第１空隙部１３１、第２空隙部１３２、第３空隙部１３３、第４空隙部１３４の角部を円弧状（Ｒ形状）としている。このようにすることで、熱膨張や振動の影響で空隙部の角部に応力が集中するがなく、配線基板１３０の破損を防止できる。
さらに、第１空隙部１３１、第２空隙部１３２、第３空隙部１３３、第４空隙部を貫通孔としている。貫通孔とすることで、空隙部全体を配線基板で囲むこととなり、切り欠き形状とした場合に比して、配線基板１３０の平面に沿う方向の剛性が高く保たれ、熱膨張や振動の影響で配線基板１３０が破損することを防止できる。
【００３７】
さらに、ガス及び温度検知装置１００では、図１に示すように、サーミスタ１５０を配線基板１３０の縁部に配置している。従って、図３に示すように、サーミスタ１５０を配線基板１３０に投影したサーミスタ投影部１３０ｃが、配線基板１３０の縁部に位置する。一般に、縁部は、配線基板内部から熱が伝わっても外部に熱が放散されやすいので、温度が上昇しにくい。従って、配線基板１３０の縁部に位置するサーミスタ投影部１３０ｃでも、電気ヒータ素子１４３から伝わった熱は配線基板１３０の外部へ放出されやすく、サーミスタ投影部１３０ｃは配線基板１３０の平面方向内部に比して低温となり、サーミスタ１５０は電気ヒータ素子１４３から発生した熱に影響されにくくなる。特に、サーミスタ投影部１３０ｃは、配線基板１３０の周縁角部（図３中左角部）に位置しているので、より一層熱を外部に放出し易くなっている。
また、サーミスタ投影部１３０ｃは、配線基板１３０のうちヒータ投影部１３０ｂから最も離れた位置となっているので、配線基板１３０を通じてヒータ投影部１３０ｂからサーミスタ投影部１３０ｃまでの熱伝導経路が最も長くなる。このため、サーミスタ１５０は、より一層、電気ヒータ素子１４３から発生した熱に影響されにくくなる。
【００３８】
また、図２に２点鎖線で示すように、ガス及び温度検知装置１００では、第１ケーシング部材１１０の通気孔１１２ｂから導入された気体（外気）を配線基板１３０の第１空隙部１３１、第２空隙部１３２、第３空隙部１３３、第４空隙部１３４まで導く経路Ｒ１，Ｒ２，Ｒ３，Ｒ４を有している。すなわち、ガス及び温度検知装置１００の外部から通気孔１１２ｂを通じて導入された気体（外気）が上記４つの空隙部まで導かれる。このため、上記４つの空隙部において、配線基板１３０を伝わる熱が気体（外気）によって外部に放散されるので、サーミスタ１５０は、電気ヒータ素子１４３から発生した熱に影響されにくくなる。さらに、２点鎖線で示すように、第１ケーシング部材１１０の通気孔１１２ｂから導入された気体（外気）をサーミスタ１５０まで導く経路Ｒ５を有している。このため、サーミスタ１５０は、ガス及び温度検知装置１００の外部から通気孔１１２ｂを通じて導入された気体（空気）によって冷却される。またこれと共に、ガス及び温度検知装置１００の外部の気温（外気温）を適切に検知することができる。なお、ガスセンサ素子収容部１１２の内側のうち通気孔１１２ｂの形成位置よりもガスセンサ素子１４０側に、通気性及び撥水性を有するフィルタ１１９が設けられている。このため、ガス及び温度検知装置１００の外部から水分が侵入することなく、外部の気体（外気）をケーシング１６０内に導入することができる。
【００３９】
さらに、図２に示すように、配線基板１３０の基板端子１３５には、ガス及び温度検知装置１００の外部と電気的に接続するコネクタピン１１８が接続される。具体的には、コネクタピン１１８のうち第１ケーシング部材１１０から端子コネクタ部１１３とは反対側に突出する基板側接続部１１８ｂを配線基板１３０の基板端子１３５に挿入し、ハンダ等によって接続することでコネクタピン１１８と配線基板１３０とが電気的に接続される。さらに、端子コネクタ部１１３に、これと嵌合する図示しないコネクタ部を有するケーブルを接続することで、コネクタピン１１８を通じて配線基板１３０を外部と電気的に接続することができる。このとき、配線基板１３０は、コネクタピン１１８を通じて外部と熱的にも接続することとなる。具体的には、配線基板１３０のうちコネクタピン１１８の周縁部の熱がコネクタピン１１８を通じてケーブルに伝わり、このケーブルから熱が外部に放散される。
【００４０】
ところで、本実施形態のガス及び温度検知装置１００では、図３に示すように、配線基板１３０のうちサーミスタ投影部１３０ｃ周縁部に基板端子１３５が位置している。従って、サーミスタ投影部１３０ｃの周縁部にコネクタピン１１８が配置されることになる。このため、配線基板１３０のサーミスタ投影部１３０ｃの周縁部の熱がコネクタピン１１８を通じてガス及び温度検知装置１００の外部に放出されるので、サーミスタ１５０は、電気ヒータ素子１４３から発生した熱に、より一層影響されにくくなる。
【００４１】
このようなガス及び温度検知装置１００は、例えば、自動車のボディや車両用空調装置のダクト等に取付けられて、外気中の排気ガス濃度の変化を検知すると共に、外気温（車室外の外気の温度）を検知することができる。具体的には、外気中の排気ガス濃度の変化が所定レベル以上となると自動的にフラップの開閉を切り替えて、自動車の内外気モードを制御すると共に、外気温に応じて車両室内の空調を自動的に制御する車両空調制御装置に用いることができる。
【００４２】
（変形形態１）
次に、実施形態のガス及び温度検知装置１００の第１の変形形態であるガス及び温度検知装置について、図面を参照しつつ説明する。実施形態のガス及び温度検知装置１００と変形形態１のガス及び温度検知装置とは、配線基板に形成した空隙部の形状・位置が異なり、その他の部分についてはほぼ同様である。従って、実施形態と異なる部分を中心に説明し、同様な部分については、説明を省略または簡略化する。
【００４３】
まず、本変形形態１のガス及び温度検知装置の配線基板２３０の平面図を図４に示す。実施形態のガス及び温度検知装置１００では、図３に示すように、配線基板１３０のヒータ投影部１３０ｂの周縁には、第１空隙部１３１、第２空隙部１３２、及び第３空隙部１３３の３つの空隙部をコの字状に配置形成した。これに対し、本変形形態１のガス及び温度検知装置では、図４に示すように、配線基板２３０のうちヒータ投影部２３０ｂの周縁には、第１空隙部２３１及び第２空隙部２３２の２つの空隙部を隣り合うようにハの字状に配置形成している。このように空隙部を形成しても、実施形態のガス及び温度検知装置１００と同様に、電気ヒータ素子１４３で発生した熱が、配線基板２３０の中間領域２３０ｄに拡がり、さらにサーミスタ投影部２３０ｃへ伝わるのを早い段階で効率良く妨げることができる。
【００４４】
特に、第２空隙部２３２は、実施形態の第２空隙部１３２と同様に、ヒータ投影部２３０ｂとサーミスタ投影部２３０ｃとを結んだ仮想直線Ｌの一部を含むように形成されている。すなわち、第２空隙部２３２は、電気ヒータ素子１４３で発生する熱が配線基板２３０を通じてサーミスタ１５０に最も伝わり易い最短熱伝導経路上に位置している。このため、実施形態のガス及び温度検知装置１００と同様に、電気ヒータ素子１４３で発生した熱が配線基板２３０の中間領域２３０ｄを通じてサーミスタ１５０に伝わるのを効率良く妨げることができる。
【００４５】
さらに、本変形形態１のガス及び温度検知装置では、第１空隙部２３１と第２空隙部２３２との間を通って、ガスセンサ素子１４０を配線基板２３０に対し配線基板２３０の厚さ方向に投影したガスセンサ投影領域２３０ｅ（２点鎖線で示す円領域）内から図示しないＩＣ等の電子部品が実装された中間領域２３０ｄ内に延びる配線２３６が形成されている。このため、この配線２３６を用いて、ガスセンサ素子１４０（電気ヒータ素子１４３、第１，第２感ガス体１４１，１４２）と、中間領域２３０ｄ内に実装されているＩＣ等の電子部品とを接続することができる。すなわち、ヒータ投影部２３０ｂの周縁部に隣り合って形成された第１空隙部２３１、第２空隙部２３２、第３空隙部２３３によって電気ヒータ素子１４３から発生する熱の伝達を妨げつつも、これらの空隙部同士の間を通るように配線２３６を形成することによって、ジャンパ線等を用いなくとも、簡単にガスセンサ素子１４０と中間領域２３０ｄ内の電子部品とを電気的に接続することができる。
【００４６】
（変形形態２）
また、上記変形形態１では、ヒータ投影部２３０ｂの周縁に第１空隙部２３１及び第２空隙部２３２の２つの空隙部を、ガスセンサ投影領域２３０ｅ（２点鎖線で示す円領域）に接するハの字状に配置形成した。しかし、図５に示す配線基板３３０のように、２つの円弧状の空隙部である第１空隙部３３１及び第２空隙部３３２をガスセンサ投影領域２３０ｅ（２点鎖線で示す円領域）に重なるように形成しても良い。このように空隙部を形成しても、実施形態及び変形形態１のガス及び温度検知装置と同様に、電気ヒータ素子１４３で発生した熱が、配線基板３３０の中間領域２３０ｄに拡がり、さらにサーミスタ投影部２３０ｃへ伝わるのを早い段階で効率良く妨げることができる。
【００４７】
以上において、本発明を実施形態及び変形形態１，２に即して説明したが、本発明は上記実施形態等に限定されるものではなく、その要旨を逸脱しない範囲で、適宜変更して適用できることはいうまでもない。
例えば、実施形態等では、ガスセンサ素子として、第１感ガス体１４１、第２感ガス体１４２、及び電気ヒータ素子１４３をアルミナ基板１４５に実装して一体としたガスセンサ素子１４０を用いた。しかし、このような構造のガスセンサ素子に限定されることはなく、例えば、ガスセンサ素子として、電気ヒータ素子を有しない感ガス体を用いて、これとは別に電気ヒータ素子を配線基板に実装するようにしても良い。また、金属コイルの表面にＳｎＯ２等の金属酸化物半導体を塗布して焼結し、ヒータ自身を感ガス体にしたガスセンサ素子を用いても良い。
【００４８】
また、実施形態等では、ガスセンサ素子１４０とサーミスタ１５０とを共に、配線基板１３０，２３０の主面１３０ｆ，２３０ｆに実装した（図２参照）。しかし、ガスセンサ素子１４０とサーミスタ１５０とを配線基板の同一面に実装する場合に限らず、互いを反対面（例えば、ガスセンサ素子１４０を主面１３０ｆ、サーミスタ１５０を裏面１３０ｇ）に実装するようにしても良い。
【図面の簡単な説明】
【図１】実施形態にかかるガス及び温度検知装置１００の分解斜視図である。
【図２】実施形態にかかるガス及び温度検知装置１００の側面視断面図である。
【図３】実施形態にかかるガス及び温度検知装置１００の配線基板１３０の平面図である。
【図４】変形形態１にかかるガス及び温度検知装置の配線基板２３０の平面図である。
【図５】変形形態２にかかるガス及び温度検知装置の配線基板３３０の平面図である。
【符号の説明】
１００　ガス及び温度検知装置
１４３　電気ヒータ素子（熱源）
１４０　ガスセンサ素子
１５０　サーミスタ（感温素子）
１３０，２３０，３３０　配線基板
１３１，２３１，３３１　第１空隙部
１３２，２３２，３３２　第２空隙部
１３３　第３空隙部
１３４　第４空隙部
１３０ｂ　ヒータ投影部（熱源投影部）
１３０ｃ　サーミスタ投影部（感温投影部）
１１０　第１ケーシング部材
１２０　第２ケーシング部材
１６０　ケーシング
１１２ｂ　通気孔
１１８　コネクタピン
１３６，２３６　配線[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a gas and temperature detecting device having a gas sensor element and a temperature sensing element.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a gas and temperature detecting device having a gas sensor element and an outside air temperature sensor is known (for example, see Patent Document 1). The gas sensor element used in the gas and temperature detecting device has a gas-sensitive body and a heater, and is used in a state where the gas-sensitive body is heated at a high temperature by being heated by the heater.
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2000-142097 (FIG. 3)
[0004]
[Problems to be solved by the invention]
However, when the gas sensor element and the temperature sensor are mounted on one substrate as in the gas and temperature detection device, heat generated by the heater is transmitted to the temperature-sensitive element through the substrate. For this reason, the temperature of the temperature-sensitive element itself may rise, and it may be impossible to appropriately detect the outside air temperature.
[0005]
The present invention has been made in view of such a situation, and prevents heat generated from a heat source of a gas sensor element from being transmitted to a temperature-sensitive element through a wiring board, and the temperature-sensitive element prevents measurement of an external object such as an outside air temperature outside the apparatus. It is an object of the present invention to provide a gas and a temperature detecting device capable of appropriately detecting a temperature without being affected by heat from a heat source.
[0006]
Means for Solving the Problems, Functions and Effects
The solution includes a gas sensor element that includes a heat source and detects a change in concentration of a specific gas, a temperature-sensitive element that detects a temperature, and a wiring board on which the gas sensor element and the temperature-sensitive element are mounted. A sensing device, wherein the wiring board is formed so as to penetrate in a thickness direction thereof, and a gas and temperature sensing device having a void portion that prevents heat from being transmitted from the heat source to the temperature-sensitive element through the wiring board. It is.
[0007]
In the gas and temperature detecting device according to the present invention, by providing the void in the wiring board, it is possible to prevent the heat generated by the heat source of the gas sensor element from being transmitted to the temperature-sensitive element through the wiring board. This is because, by providing the void portion in the wiring board, this portion is replaced with gas and the thermal conductivity is reduced. For this reason, in the gas and temperature detection device of the present invention, the influence of the heat from the heat source on the temperature-sensitive element is prevented, and the temperature of the measurement target, for example, the temperature outside the gas and temperature detection device (such as the outside air temperature outside the vehicle compartment, etc.) ) Can be appropriately detected by the temperature-sensitive element.
[0008]
As the gas sensor element including the heat source, for example, a gas-sensitive body and a heater which are integrally formed, a gas-sensitive body and a heater are separated, and a heater itself is a gas-sensitive body ( For example, a metal coil semiconductor coated with a metal oxide semiconductor such as SnO2 and sintered may be used. The temperature sensing element may be any element that can detect temperature, and a typical example is a thermistor. In addition, the void portion penetrating the wiring board in the thickness direction includes a notch having a concave outer peripheral surface of the wiring board, in addition to the through hole formed in the wiring board.
[0009]
Further, in the gas and temperature detection device, the gap portion of the wiring board may include a heat source projection unit that projects the heat source of the gas sensor element onto the wiring board in a thickness direction of the wiring board, and the temperature sensing element. A gas and temperature detecting device including a part of an imaginary straight line connecting the element to the wiring substrate and a temperature-sensitive projection unit projecting the wiring substrate in a thickness direction of the wiring substrate may be used.
[0010]
In the gas and temperature detection device according to the present invention, the void portion of the wiring board is formed so as to include a part of a virtual straight line connecting the heat source projection unit and the temperature-sensitive projection unit. That is, the void portion of the wiring board is located on the shortest heat conduction path where heat generated by the heat source of the gas sensor element is most easily transmitted to the temperature-sensitive element through the wiring board. Therefore, it is possible to efficiently prevent the heat generated by the heat source from being transmitted to the temperature-sensitive element through the wiring board.
[0011]
Furthermore, in any one of the above gas and temperature detecting devices, the void portion of the wiring board is a heat source projection unit that projects the heat source of the gas sensor element with respect to the wiring board in a thickness direction of the wiring board; It is preferable to use a gas and temperature detecting device formed on at least one of the peripheral portions.
[0012]
In the gas and temperature detection device of the present invention, the void portion of the wiring board is formed on at least one of the heat source projection portion that projects the heat source of the gas sensor element on the wiring substrate in the thickness direction of the wiring substrate and the peripheral portion thereof. ing. That is, the void is formed at a position near the heat source in the wiring board. For this reason, the gas and temperature detection device of the present invention can efficiently prevent the heat generated by the heat source from being transmitted to the temperature-sensitive element at an early stage.
[0013]
Further, in the gas and temperature detecting device, the gap portion is at least two adjacent gap portions, and the wiring board has a wire and a temperature having a wiring passing between the at least two adjacent gap portions. A detection device may be used.
[0014]
The wiring that passes between at least two adjacent gaps formed in at least one of the heat source projection part and the peripheral part thereof is formed on the wiring board of the gas and temperature detection device of the present invention. Therefore, by using this wiring, it is possible to electrically connect an electronic component located in a region closer to the heat source with respect to the heat source or the gap and an electronic component located in a region opposite to the heat source. In other words, the formation of at least two adjacent air gaps in at least one of the heat source projection unit and the peripheral edge thereof prevents transmission of heat generated from the heat source, but easily allows the heat source or the area closer to the heat source than the air gap. And the electronic component located in the area on the opposite side of the heat source can be electrically connected.
[0015]
Further, in any one of the above gas and temperature detecting devices, the void portion of the wiring board is a temperature-sensitive projection unit that projects the temperature-sensitive element on the wiring board in a thickness direction of the wiring board, and a temperature-sensitive projection unit. It is preferable to use a gas and temperature detecting device formed on at least one of the peripheral portions.
[0016]
In the gas and temperature detection device of the present invention, the void portion of the wiring board is formed on at least one of the temperature-sensitive projection portion that projects the temperature-sensitive element on the wiring substrate in the thickness direction of the wiring substrate and the peripheral portion thereof. ing. That is, the void is formed at a position near the temperature-sensitive element in the wiring board. For this reason, it is possible to prevent heat transmitted from the heat source to the vicinity of the temperature-sensitive element through the wiring board from being finally transmitted to the temperature-sensitive element.
[0017]
Further, in any one of the gas and temperature detecting devices described above, it is preferable that a corner of the gap of the wiring board is formed in an arc shape.
[0018]
In the gas and temperature detecting device, stress may be generated in the wiring board due to a difference in thermal expansion between the electronic component such as a gas sensor element and a temperature sensing element mounted on the wiring board and the wiring board or an external vibration. For this reason, for example, if the outer corner of the void formed in the wiring board has a square shape, stress concentrates on this corner, and there is a possibility that a crack may occur in the wiring board from this portion. On the other hand, in the gas and temperature detecting device of the present invention, the corners of the voids of the wiring board are formed in an arc shape. By doing so, stress is not concentrated on the corners of the gap due to the influence of the difference in thermal expansion or vibration, and damage to the wiring board can be prevented. In addition, the corner | angular part of a space | gap part is an arc shape (R shape), and the thing of an elliptical arc shape is mentioned, for example. Therefore, the case where the corner portion is formed in an arc shape, and the entire void portion becomes an elliptical shape or a circular shape is also included.
[0019]
Further, in any one of the gas and temperature detecting devices described above, the void portion of the wiring board may be a gas and temperature detecting device that is a through hole.
[0020]
In the gas and temperature detection device, stress may be generated in the wiring board due to a difference in thermal expansion between the electronic component such as a gas sensor element or a temperature-sensitive element mounted on the wiring board and the wiring board or an external vibration. For this reason, when the void portion is, for example, a cutout in which the outer peripheral surface of the wiring substrate is concave, one narrow portion of the wiring substrate is formed. Stiffness in the direction along the direction may decrease. For this reason, there is a possibility that a crack may occur in the wiring board from the cutout portion. On the other hand, in the gas and temperature detecting device of the present invention, the void portion of the wiring board is a through hole. For this reason, the entire void portion is surrounded by the wiring substrate, and two narrow portions are formed with the void portion interposed therebetween, so that the direction along the plane of the wiring substrate is smaller than when notches are formed. The rigidity of the wiring board is kept high, and it is possible to prevent the wiring board from being damaged by the influence of the difference in thermal expansion or vibration.
[0021]
Further, in any one of the above gas and temperature detecting devices, it is preferable that the temperature sensing element is a gas and temperature detecting device arranged at an edge of the wiring board.
[0022]
Generally, since the edge of the wiring board is close to the outside of the board, heat is easily released to the outside, and the temperature is lower than that of the inside of the wiring board in the planar direction. In the gas and temperature detection device according to the present invention, the temperature-sensitive element is disposed at the edge of the wiring board. Therefore, the temperature-sensitive projection unit that projects the temperature-sensitive element onto the wiring board becomes an edge of the wiring board. As a result, the heat transmitted from the heat source to the temperature-sensitive projection unit is released to the outside of the substrate, and the temperature-sensitive projection unit has a lower temperature than the inside of the wiring board in the planar direction. Be less affected.
[0023]
Further, in the gas and temperature detecting device, the temperature-sensitive element may be a gas and temperature detecting device arranged at a position farthest from the heat source of the gas sensor element in the edge portion of the wiring board. good.
[0024]
In the gas and temperature detection device according to the present invention, the temperature sensing element is disposed at a position farthest from the heat source of the gas sensor element in the edge of the wiring board. For this reason, the temperature-sensitive element is further less affected by the heat generated from the heat source.
[0025]
Further, any one of the above gas and temperature detecting devices, further comprising a casing for accommodating the gas sensor element, the temperature sensing element, and the wiring board, wherein the casing introduces a gas outside the casing into the inside of the casing. It is preferable that the gas and temperature detection device include a vent hole to be formed and a path for guiding the gas introduced from the vent hole to the void portion of the wiring board.
[0026]
In the gas and temperature detecting device according to the present invention, the gas introduced from the outside through the vent hole is guided to the gap of the wiring board. For this reason, in the gap, heat transmitted through the wiring board is radiated to the outside through the gas. Therefore, the temperature-sensitive element is less affected by the heat generated from the heat source.
[0027]
Further, in the gas and temperature detecting device, the casing may be a gas and temperature detecting device having a path for guiding the gas introduced from the ventilation hole to the temperature-sensitive element of the wiring board.
[0028]
In the gas and temperature detecting device of the present invention, the gas introduced from the outside through the vent hole is guided to the temperature-sensitive element. Therefore, the temperature sensing element is cooled by the gas introduced from the outside. At the same time, it is possible to appropriately detect the temperature outside the casing (outside temperature).
[0029]
Further, in any one of the above gas and temperature detecting devices, a peripheral portion of a temperature-sensitive projection unit that projects the temperature-sensitive element from the wiring substrate to the wiring substrate in a thickness direction of the wiring substrate, It is preferable that the gas and temperature detecting device is formed by fixing a connector pin electrically connected to the outside of the gas and temperature detecting device.
[0030]
In the gas and temperature detection device, for example, by connecting an electric wire having a terminal fitting engaged with the connector pin at one end to the connector pin from the outside, the wiring board is electrically connected to the outside through the connector pin. At this time, the wiring board is also thermally connected to the outside through the connector pins. Specifically, the heat of the peripheral portion of the connector pin in the wiring board is transmitted to the wiring through the connector pin, and the heat is radiated from the wiring to the outside. Therefore, in the gas and temperature detecting device of the present invention, connector pins for electrically connecting to the outside are arranged on the peripheral portion of the temperature-sensitive projection section of the wiring board. By doing so, the heat at the peripheral portion of the temperature-sensitive projection portion of the wiring board is released to the outside through the connector pins, so that the temperature-sensitive element is less affected by the heat generated from the heat source.
[0031]
BEST MODE FOR CARRYING OUT THE INVENTION
(Embodiment)
A gas and temperature detecting device 100 according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the gas and temperature detection device 100 of the present embodiment includes a first casing member 110, a second casing member 120, and a wiring board 130. The wiring board 130 is housed in a casing 160 integrated by combining the first casing member 110 and the second casing member 120.
The first casing member 110 has a lid shape integrally molded with resin, and has a gas sensor element accommodating section 112 for accommodating the gas sensor element 140, a vent 112b for introducing outside air into the casing 160, and a terminal connector section for electrically connecting to the outside. 113. The second casing member 120 is a box shape integrally molded with resin, and has a mounting portion 122 for mounting the gas and temperature detecting device 100 to a vehicle body, a duct of a vehicle air conditioner, or the like.
[0032]
The wiring board 130 is made of a glass cloth base epoxy resin, and a gas sensor element 140 for detecting a gas concentration and a thermistor 150 for detecting an outside air temperature are mounted on a main surface 130f.
Here, FIG. 2 is a cross-sectional side view of the gas and temperature detecting device 100 integrated with the gas and temperature detecting device 100 shown in FIG. As shown in FIG. 2, the gas sensor element 140 has an alumina substrate 145 on which a first gas sensitive body 141, a second gas sensitive body 142, and an electric heater element 143 are mounted, and has a ventilation hole 146b and surrounds the alumina substrate 145. The outer cylinder 146 and four element terminal portions 147 are provided. The first gas sensing element 141 has a sensor resistance value that changes due to a change in the concentration of an oxidizing gas such as NOx (for example, a material mainly composed of WO3). The second gas sensing element 142 has a sensor resistance value that changes due to a change in the concentration of a reducing gas such as HC or CO (for example, a sensor mainly composed of SnO2). The electric heater element 143 is for heating the first and second gas-sensitive bodies 141 and 142. The element terminal portion 147 has one end connected to the first and second gas-sensitive bodies 141 and 142, the electric heater element 143, and the common GND, and the other end extending to the outside of the outer cylinder 146. Such a gas sensor element 140 is mounted on the wiring board 130 by connecting the element terminal portion 147 to a board terminal 138 provided on the wiring board 130.
In the present embodiment, the electric heater element 143 corresponds to a heat source, and the thermistor 150 corresponds to a temperature-sensitive element. Needless to say, the gas sensor element 140 is not limited to the above configuration.
[0033]
Next, a plan view of the wiring board 130 is shown in FIG. As shown in FIG. 3, the wiring board 130 penetrates the wiring board 130 in the thickness direction in order to prevent heat generated by the electric heater element 143 of the gas sensor element 140 from being transmitted to the thermistor 150 through the wiring board 130. A first gap 131, a second gap 132, a third gap 133, and a fourth gap 134 having a slit shape are formed. In particular, the second gap 132 and the fourth gap 134 are virtual straight lines connecting the heater projection unit 130b that projects the electric heater element 143 onto the wiring board 130 and the thermistor projection unit 130c that projects the thermistor 150 onto the wiring board 130. It is formed to include a part of L. That is, the second gap 132 and the fourth gap 134 are located on the shortest heat conduction path where heat generated by the electric heater element 143 is most easily transmitted to the thermistor 150 through the wiring board 130. Therefore, it is possible to efficiently prevent the heat generated by the electric heater element 143 from being transmitted to the thermistor 150 through the wiring board 130.
[0034]
Further, the first gap portion 131, the second gap portion 132, and the third gap portion 133 are formed on the periphery of a heater projection portion 130b that projects the electric heater element 143 onto the wiring board 130. That is, the first gap 131, the second gap 132, and the third gap 133 are formed at a position near the electric heater element 143 in the wiring board 130.
Therefore, the heat generated by the electric heater element 143 spreads to an intermediate region 130d located between the heater projection unit 130b and the thermistor projection unit 130c of the wiring board 130, and is transmitted to the thermistor projection unit 130c at an early stage. It can be hindered efficiently.
Further, the fourth void portion 134 is formed at the periphery of the thermistor projection portion 130c that projects the thermistor 150 onto the wiring substrate 130 in the thickness direction of the wiring substrate 130. That is, the fourth gap 134 is formed at a position near the thermistor 150 in the wiring board 130. For this reason, the heat transmitted from the electric heater element 143 to the vicinity of the thermistor projection unit 130c through the wiring board 130 can be hardly transmitted to the thermistor 150 finally.
[0035]
Further, in the gas and temperature detection device 100, as shown in FIG. 3, the gas passes between the first gap 131 and the second gap 132 and between the second gap 132 and the third gap 133, Electronic components (not shown) such as ICs, capacitors, and resistors are mounted in a gas sensor projection area 130e (a circle area shown by a two-dot chain line) in which the gas sensor element 140 is projected onto the wiring board 130 in the thickness direction of the wiring board 130. A wiring 136 extending into the intermediate region 130d is formed. Therefore, the wiring 136 is used to connect the gas sensor element 140 (the electric heater element 143, the first and second gas-sensitive bodies 141 and 142) to electronic components such as ICs mounted in the intermediate region 130d. can do. That is, while the first gap 131, the second gap 132, and the third gap 133 formed adjacent to the peripheral edge of the heater projection section 130b prevent the heat generated from the electric heater element 143 from being transmitted, By forming the wiring 136 so as to pass between the voids, the gas sensor element 140 and the electronic components in the intermediate region 130d can be easily electrically connected without using a jumper wire or the like.
[0036]
By the way, in the gas and temperature detecting device 100, a stress is applied to the wiring board 130 due to a difference in thermal expansion between the electronic parts such as the gas sensor element 140 and the thermistor 150 mounted on the wiring board 130 and the wiring board 130, and a vibration of an automobile or the like. May occur. On the other hand, in the gas and temperature detecting device 100, as shown in FIG. 3, the corners of the first gap 131, the second gap 132, the third gap 133, and the fourth gap 134 formed in the wiring board 130. The portion has an arc shape (R shape). By doing so, stress does not concentrate on the corners of the gap due to the effects of thermal expansion and vibration, and thus the damage of the wiring board 130 can be prevented.
Further, the first gap 131, the second gap 132, the third gap 133, and the fourth gap are formed as through holes. By forming the through hole, the entire void portion is surrounded by the wiring board, and the rigidity in the direction along the plane of the wiring board 130 is maintained higher than in the case of the cutout shape, and the influence of thermal expansion and vibration is obtained. This can prevent the wiring board 130 from being damaged.
[0037]
Further, in the gas and temperature detecting device 100, as shown in FIG. 1, the thermistor 150 is arranged at the edge of the wiring board 130. Therefore, as shown in FIG. 3, the thermistor projection unit 130 c that projects the thermistor 150 onto the wiring board 130 is located at the edge of the wiring board 130. Generally, even when heat is transmitted from the inside of the wiring board to the outside, heat is easily radiated to the outside, so that the temperature does not easily rise. Therefore, even in the thermistor projection section 130c located at the edge of the wiring board 130, the heat transmitted from the electric heater element 143 is easily radiated to the outside of the wiring board 130, and the thermistor projection section 130c is smaller than the inside of the wiring board 130 in the plane direction. As a result, the temperature becomes low, and the thermistor 150 is hardly affected by the heat generated from the electric heater element 143. In particular, since the thermistor projection section 130c is located at the peripheral corner (left corner in FIG. 3) of the wiring board 130, it is easier to release heat to the outside.
Further, since the thermistor projection unit 130c is located farthest from the heater projection unit 130b in the wiring board 130, the heat conduction path from the heater projection unit 130b to the thermistor projection unit 130c through the wiring board 130 is the longest. . Therefore, the thermistor 150 is further less affected by the heat generated from the electric heater element 143.
[0038]
Further, as indicated by a two-dot chain line in FIG. 2, in the gas and temperature detecting device 100, the gas (outside air) introduced from the vent 112 b of the first casing member 110 is supplied to the first gap 131 of the wiring board 130, There are paths R1, R2, R3, R4 leading to the second gap 132, the third gap 133, and the fourth gap 134. That is, the gas (outside air) introduced from the outside of the gas and temperature detection device 100 through the vent hole 112b is guided to the four gaps. For this reason, in the above four voids, the heat transmitted through the wiring board 130 is radiated to the outside by the gas (outside air), so that the thermistor 150 is hardly affected by the heat generated from the electric heater element 143. Further, as shown by the two-dot chain line, the first casing member 110 has a path R5 for guiding the gas (outside air) introduced from the vent 112b to the thermistor 150. Therefore, the thermistor 150 is cooled by the gas (air) introduced from the outside of the gas and temperature detection device 100 through the vent 112b. At the same time, the temperature outside the gas and temperature detecting device 100 (outside air temperature) can be appropriately detected. Note that a filter 119 having air permeability and water repellency is provided on the gas sensor element 140 side of the inside of the gas sensor element accommodating portion 112 with respect to the position where the vent 112b is formed. Therefore, an external gas (outside air) can be introduced into the casing 160 without moisture entering from outside the gas and temperature detection device 100.
[0039]
Further, as shown in FIG. 2, connector pins 118 that are electrically connected to the outside of the gas and temperature detecting device 100 are connected to the board terminals 135 of the wiring board 130. Specifically, the board-side connecting portion 118b of the connector pin 118 protruding from the first casing member 110 on the side opposite to the terminal connector portion 113 is inserted into the board terminal 135 of the wiring board 130 and connected by solder or the like. Thus, the connector pins 118 and the wiring board 130 are electrically connected. Further, by connecting a cable having a connector part (not shown) to be fitted to the terminal connector part 113, the wiring board 130 can be electrically connected to the outside through the connector pins 118. At this time, the wiring board 130 is also thermally connected to the outside through the connector pins 118. Specifically, the heat of the peripheral portion of the connector pin 118 of the wiring board 130 is transmitted to the cable through the connector pin 118, and the heat is radiated from the cable to the outside.
[0040]
By the way, in the gas and temperature detecting device 100 of the present embodiment, as shown in FIG. 3, the substrate terminal 135 is located on the periphery of the thermistor projection portion 130 c of the wiring substrate 130. Therefore, the connector pins 118 are arranged on the periphery of the thermistor projection unit 130c. Therefore, heat at the peripheral edge of the thermistor projecting portion 130c of the wiring board 130 is released to the outside of the gas and the temperature detecting device 100 through the connector pins 118, so that the thermistor 150 is more sensitive to the heat generated from the electric heater element 143. It is less likely to be affected.
[0041]
Such a gas and temperature detecting device 100 is attached to, for example, a body of an automobile or a duct of an air conditioner for a vehicle, and detects a change in the concentration of exhaust gas in the outside air, and also detects an outside air temperature (the outside air outside the vehicle compartment). Temperature) can be detected. Specifically, when the change in the exhaust gas concentration in the outside air exceeds a predetermined level, the opening and closing of the flap is automatically switched to control the inside and outside air mode of the vehicle, and the air conditioning in the vehicle compartment is automatically performed according to the outside temperature. It can be used for a vehicle air-conditioning control device that performs dynamic control.
[0042]
(Modification 1)
Next, a gas and temperature detection device that is a first modification of the gas and temperature detection device 100 of the embodiment will be described with reference to the drawings. The gas and temperature detecting device 100 of the embodiment differs from the gas and temperature detecting device of Modification 1 in the shape and position of the void formed in the wiring board, and the other portions are substantially the same. Therefore, the description will be focused on the parts different from the embodiment, and the description of the same parts will be omitted or simplified.
[0043]
First, FIG. 4 is a plan view of the wiring board 230 of the gas and temperature detecting device according to the first modification. In the gas and temperature detection device 100 of the embodiment, as shown in FIG. 3, the first gap 131, the second gap 132, and the third gap 133 are formed around the periphery of the heater projection 130 b of the wiring board 130. The three voids were formed in a U-shape. On the other hand, in the gas and temperature detecting device according to the first modification, as shown in FIG. 4, the first gap portion 231 and the second gap portion 232 are formed around the periphery of the heater projection portion 230 b of the wiring board 230. The two void portions are arranged and formed in a C shape so as to be adjacent to each other. Even when the gap is formed in this way, the heat generated by the electric heater element 143 spreads to the intermediate region 230d of the wiring board 230 and further to the thermistor projection unit 230c, as in the gas and temperature detection device 100 of the embodiment. Transmission can be prevented efficiently at an early stage.
[0044]
In particular, like the second gap 132 of the embodiment, the second gap 232 is formed to include a part of a virtual straight line L connecting the heater projection 230b and the thermistor projection 230c. That is, the second gap 232 is located on the shortest heat conduction path where heat generated by the electric heater element 143 is most easily transmitted to the thermistor 150 through the wiring board 230. Therefore, similarly to the gas and temperature detection device 100 of the embodiment, it is possible to efficiently prevent the heat generated by the electric heater element 143 from being transmitted to the thermistor 150 through the intermediate region 230d of the wiring board 230.
[0045]
Furthermore, in the gas and temperature detecting device of the first modification, the gas sensor element 140 is projected between the first gap 231 and the second gap 232 on the wiring board 230 in the thickness direction of the wiring board 230. A wiring 236 extending from the gas sensor projection area 230e (a circle area indicated by a two-dot chain line) to an intermediate area 230d on which electronic components such as an IC (not shown) are mounted is formed. Therefore, the wiring 236 is used to connect the gas sensor element 140 (the electric heater element 143 and the first and second gas-sensitive bodies 141 and 142) to electronic components such as ICs mounted in the intermediate region 230d. can do. That is, while the first gap 231, the second gap 232, and the third gap 233 formed adjacent to the peripheral edge of the heater projection 230 b prevent transmission of heat generated from the electric heater element 143, By forming the wiring 236 so as to pass between the voids, the gas sensor element 140 and the electronic components in the intermediate region 230d can be easily electrically connected without using a jumper wire or the like.
[0046]
(Modification 2)
Further, in the first modification, two gaps, that is, the first gap 231 and the second gap 232 are formed on the periphery of the heater projection 230b so as to be in contact with the gas sensor projection area 230e (circular area indicated by a two-dot chain line). It was arranged and formed in a letter shape. However, like the wiring board 330 shown in FIG. 5, the first gap 331 and the second gap 332, which are two arc-shaped gaps, are overlapped with the gas sensor projection area 230e (a circle area shown by a two-dot chain line). May be formed. Even when the gap is formed in this manner, the heat generated by the electric heater element 143 spreads to the intermediate region 230d of the wiring board 330, and thermistor projection is performed, similarly to the gas and temperature detection devices of the embodiment and the first modification. The transmission to the section 230c can be efficiently prevented at an early stage.
[0047]
In the above, the present invention has been described with reference to the embodiment and Modifications 1 and 2. However, the present invention is not limited to the above-described embodiment and the like, and may be appropriately modified and applied without departing from the gist thereof. It goes without saying that you can do it.
For example, in the embodiment and the like, the gas sensor element 140 in which the first gas-sensitive body 141, the second gas-sensitive body 142, and the electric heater element 143 are mounted on the alumina substrate 145 and integrated is used as the gas sensor element. However, the present invention is not limited to the gas sensor element having such a structure. For example, a gas sensing element having no electric heater element may be used as the gas sensor element, and the electric heater element may be separately mounted on the wiring board. You may do it. Alternatively, a gas sensor element in which a metal oxide semiconductor such as SnO2 is applied to the surface of the metal coil and sintered, and the heater itself is used as a gas-sensitive body may be used.
[0048]
In the embodiment and the like, both the gas sensor element 140 and the thermistor 150 are mounted on the main surfaces 130f, 230f of the wiring boards 130, 230 (see FIG. 2). However, the present invention is not limited to the case where the gas sensor element 140 and the thermistor 150 are mounted on the same surface of the wiring board. Is also good.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a gas and temperature detecting device 100 according to an embodiment.
FIG. 2 is a side sectional view of the gas and temperature detecting device 100 according to the embodiment.
FIG. 3 is a plan view of a wiring board 130 of the gas and temperature detecting device 100 according to the embodiment.
FIG. 4 is a plan view of a wiring board 230 of the gas and temperature detecting device according to Modification 1.
FIG. 5 is a plan view of a wiring board 330 of the gas and temperature detecting device according to Modification 2.
[Explanation of symbols]
100 Gas and temperature detector
143 Electric heater element (heat source)
140 Gas sensor element
150 Thermistor (temperature sensing element)
130, 230, 330 Wiring board
131, 231, 331 First void
132, 232, 332 Second gap
133 Third void
134 4th void
130b Heater projection unit (heat source projection unit)
130c Thermistor projection unit (temperature sensing projection unit)
110 first casing member
120 Second casing member
160 casing
112b vent
118 Connector pin
136,236 wiring

Claims

A gas sensor element that detects a change in concentration of a specific gas including a heat source,
A temperature sensing element for detecting temperature,
A wiring board on which the gas sensor element and the temperature sensitive element are mounted,
A gas and temperature sensing device comprising:
The gas and temperature detection device, wherein the wiring substrate is formed so as to penetrate in a thickness direction thereof, and has a void portion that prevents heat from being transmitted from the heat source to the temperature-sensitive element through the wiring substrate.

The gas and temperature detection device according to claim 1,
The void portion of the wiring substrate is a heat source projection unit that projects the heat source of the gas sensor element onto the wiring substrate in a thickness direction of the wiring substrate, and the thickness of the wiring substrate with respect to the wiring substrate. Gas and a temperature detecting device including a part of a virtual straight line connecting a temperature-sensitive projection unit projected in a vertical direction.

The gas and temperature detecting device according to claim 1 or 2,
The gap portion of the wiring board is formed on at least one of a heat source projection portion that projects the heat source of the gas sensor element on the wiring substrate in a thickness direction of the wiring substrate and a gas and a temperature formed on a peripheral portion thereof. Detection device.

It is a gas and temperature detection device according to claim 3,
The gap is at least two adjacent gaps,
The gas and temperature detection device, wherein the wiring substrate has a wiring passing between the at least two adjacent gaps.

It is a gas and temperature detection device according to any one of claims 1 to 4,
The gap portion of the wiring board is formed by at least one of a temperature-sensitive projection portion that projects the temperature-sensitive element onto the wiring substrate in a thickness direction of the wiring substrate and a gas and temperature detection formed on a peripheral portion thereof. apparatus.

It is a gas and temperature detection device according to any one of claims 1 to 5,
A gas and temperature detecting device, wherein a corner of the gap portion of the wiring board is formed in an arc shape.

It is a gas and temperature detection device according to any one of claims 1 to 6,
The gas and temperature detecting device, wherein the void portion of the wiring substrate is a through hole.

It is a gas and temperature detection device according to any one of claims 1 to 7,
The temperature and temperature sensing device is a gas and temperature detection device arranged at an edge of the wiring board.

It is a gas and temperature detection device according to claim 8,
The temperature and temperature sensing device is a device in which the temperature-sensitive element is disposed at a position of the edge of the wiring board farthest from the heat source of the gas sensor element.

It is a gas and temperature detection device according to any one of claims 1 to 9,
The gas sensor element, the temperature sensing element, and a casing that houses the wiring board,
The casing is
A vent for introducing gas outside the casing into the casing,
A path for guiding the gas introduced from the vent hole to the gap of the wiring board.

It is a gas and temperature detecting device according to claim 10,
The gas and temperature detecting device, wherein the casing has a path for guiding the gas introduced from the vent hole to the temperature-sensitive element of the wiring board.

The gas and temperature detecting device according to any one of claims 1 to 11, wherein the temperature-sensitive element of the wiring board is projected onto the wiring board in a thickness direction of the wiring board. A gas and temperature detection device, wherein a connector pin that is electrically connected to the outside of the gas and temperature detection device is fixed to a peripheral portion of the temperature projection unit.